System and method for controlling an air conditioning system and an outdoor apparatus of the system

ABSTRACT

A method for controlling an air conditioning system, an outdoor apparatus of an air conditioning system and an air conditioning system are provided. The method includes: obtaining a working mode of the air conditioning system and starting a variable-frequency compressor in an outdoor apparatus of the air conditioning system according to the working mode; obtaining a target refrigerant saturation temperature; performing a variable-frequency control on the variable-frequency compressor according to the target refrigerant saturation temperature; during the variable-frequency control, obtaining a working time of the variable-frequency compressor and a stop-start number of time of the variable-frequency compressor in a first predetermined period; and adjusting the target refrigerant saturation temperature according to the working time of the variable-frequency compressor and the stop-start number of time of the variable-frequency compressor in the first predetermined time.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority of Chinese PatentApplication No. 201410028403.7, filed with State Intellectual PropertyOffice on Jan. 21, 2014, the entire content of which is incorporatedherein by reference.

FIELD

Embodiments of the present invention generally relate to an airconditioning technology field, and more particularly, to a method forcontrolling an air conditioning system, an outdoor apparatus of an airconditioning system and an air conditioning system.

BACKGROUND

With the increasing development of the air conditioning technology, theDC variable-frequency air conditioner draws more and more attentions.Currently, all conventional variable-frequency air conditions needdedicated installation, and the indoor apparatus and the outdoorapparatus need special communication mode so as to control thecompressor in the outdoor apparatus.

A structure of a conventional variable-frequency air conditioning systemis shown in FIG. 1A. The outdoor apparatus receives a series of signalsbased on the specific transmission rule and sent from the indoorapparatus, including the on-off signal, the temperature determinationsignal and the indoor temperature signal, such that the compressor inthe outdoor apparatus can be controlled to operate with certainfrequency and the working frequency of the compressor can be adjustedaccording to the indoor temperature. In order to implement the controlof each element in the outdoor apparatus, the indoor apparatus isrequired to send corresponding signals to the outdoor apparatus, suchthat the air conditioning system has disadvantages of complex structureand high cost.

SUMMARY

Embodiments of the present invention seek to solve at least one of theproblems existing in the related art to at least some extent.

Embodiments of a first broad aspect of the present invention provide amethod for controlling an air conditioning system. The method includessteps of: obtaining a working mode of the air conditioning system andstarting a variable-frequency compressor in an outdoor apparatus of theair conditioning system according to the working mode; obtaining atarget refrigerant saturation temperature; performing avariable-frequency control on the variable-frequency compressoraccording to the target refrigerant saturation temperature; during thevariable-frequency control, obtaining a working time of thevariable-frequency compressor and a stop-start number of time of thevariable-frequency compressor in a first predetermined period; andadjusting the target refrigerant saturation temperature according to theworking time of the variable-frequency compressor and the stop-startnumber of time of the variable-frequency compressor in the firstpredetermined time.

With the method for controlling the air conditioning system according toembodiments of the present invention, the variable-frequency control isperformed on the variable-frequency compressor in the outdoor apparatusby obtaining the target refrigerant saturation temperature. During thevariable-frequency control for the variable-frequency compressor, thetarget refrigerant saturation temperature is adjusted according to theworking time of the variable-frequency compressor and the stop-startnumber of time of the variable-frequency compressor in the firstpredetermined period, such that the variable-frequency compressor can becontrolled independent from the indoor apparatus and withouttransmitting corresponding control parameters between the indoorapparatus and the outdoor apparatus via a specific communication, thussaving the transmission of control parameters, reducing a complexity ofthe air conditioning system and improving a reliability of the airconditioning system.

In some embodiments, obtaining a working mode of the air conditioningsystem includes receiving an on-off instruction and a mode optioninstruction sent from a remote, a line controller or an indoor apparatusof the air conditioning system via a communicator in the outdoorapparatus.

In some embodiments, the method for controlling the air conditioningsystem further includes setting an adjusted target refrigerantsaturation temperature as the refrigerant saturation temperature of theoutdoor apparatus in a next start, when the outdoor apparatus isstopped.

In some embodiments, adjusting the target refrigerant saturationtemperature according to the working time of the variable-frequencycompressor and the stop-start number of time of the variable-frequencycompressor in the first predetermined time includes: determining whetherthe working time of the variable-frequency compressor is larger than orequal to a first time threshold; if yes, obtaining the stop-start numberof time of the variable-frequency compressor in the first predeterminedperiod; and if the stop-start number of time of the variable-frequencycompressor in the first predetermined period is larger than or equal toa first predetermined number of time threshold, adjusting the targetrefrigerant saturation temperature according to a predetermined steplength.

In some embodiments, when the working mode is a heating mode, the targetrefrigerant saturation temperature is reduced by the predetermined steplength and the working time of the variable-frequency compressor returnsto zero; when the working mode is a refrigerating mode, the targetrefrigerant saturation temperature is increased by the predeterminedstep length and the working time of the variable-frequency compressorreturns to zero.

In some embodiments, obtaining a target refrigerant saturationtemperature includes: detecting a current ambient temperature of theoutdoor apparatus, when the outdoor apparatus is started for a firsttime in a predetermined working cycle; and determining the targetrefrigerant saturation temperature according to the current ambienttemperature of the outdoor apparatus.

In some embodiments, a first pressure detecting signal is detected via afirst pressure sensor disposed at an inlet of the variable-frequencycompressor, when the working mode is a refrigerating mode.

In some embodiments, a second pressure detecting signal is detected viaa second pressure sensor disposed at an outlet of the variable-frequencycompressor, when the working mode is a heating mode.

In some embodiments, performing a variable-frequency control on thevariable-frequency compressor according to the target refrigerantsaturation temperature includes: generating a current refrigerantsaturation temperature by selecting one of the first pressure detectingsignal and the second pressure detecting signal according to the workingmode; and performing the variable-frequency control on thevariable-frequency compressor according to the target refrigerantsaturation temperature and the current refrigerant saturationtemperature.

In some embodiments, the method for controlling the air conditioningsystem further includes: controlling the outdoor apparatus to delay asecond predetermined period to start or stop after receiving the on-offinstruction.

Embodiments of a second broad aspect of the present invention provide anoutdoor apparatus of an air conditioning system. The outdoor apparatusincludes: a variable-frequency compressor; a controller configured tocontrol the variable-frequency compressor and including: a start moduleconfigured to obtain a working mode of the air conditioning system andto start the variable-frequency compressor according to the working modeof the air condition; a temperature control module configured to obtaina target refrigerant saturation temperature, to obtain a working time ofthe variable-frequency compressor and a stop-start number of time of thevariable-frequency compressor in a first predetermined period during anvariable-frequency control for the variable-frequency compressor, and toadjust the target refrigerant saturation temperature according to theworking time of the variable-frequency compressor and the stop-startnumber of time of the variable-frequency compressor in the firstpredetermined period; and a variable-frequency control module configuredto perform the variable-frequency control on the variable-frequencycompressor according to the target refrigerant saturation temperature.

With the outdoor apparatus of the air conditioning system, thevariable-frequency control is performed on the variable-frequencycompressor in the outdoor apparatus by obtaining the target refrigerantsaturation temperature. During the variable-frequency control for thevariable-frequency compressor, the target refrigerant saturationtemperature is adjusted according to the working time of thevariable-frequency compressor and the stop-start number of time of thevariable-frequency compressor in the first predetermined period, suchthat the variable-frequency compressor can be controlled independentfrom an indoor apparatus and without transmitting corresponding controlparameters between the indoor apparatus and the outdoor apparatus via aspecific communication, thus saving the transmission of controlparameters, reducing a complexity of the air conditioning system andimproving a reliability of the air conditioning system.

In some embodiments, the temperature control module is furtherconfigured to set an adjusted target refrigerant saturation temperatureas the refrigerant saturation temperature of the outdoor apparatus in anext start, when the outdoor apparatus is stopped.

In some embodiments, the temperature control module is furtherconfigured to adjust the target refrigerant saturation temperatureaccording to a predetermined step length, when the working time of thevariable-frequency compressor is larger than or equal to a first timethreshold and the stop-start number of time of the variable-frequencycompressor in the first predetermined period is larger than or equal toa first predetermined number of time threshold.

In some embodiments, when the working mode is a heating mode, thetemperature control module reduces the target refrigerant saturationtemperature by the predetermined step length and return the working timeof the variable-frequency compressor to zero; when the working mode is arefrigerating mode, the temperature control module increases the targetrefrigerant saturation temperature by the predetermined step length andreturn the working time of the variable-frequency compressor to zero.

In some embodiments, the outdoor apparatus further includes atemperature sensor configured to detect a current ambient temperature ofthe outdoor apparatus, wherein the temperature control module determinesthe target refrigerant saturation temperature according to the currentambient temperature of the outdoor apparatus, when the outdoor apparatusis started for the first time in a predetermined working cycle.

In some embodiments, the outdoor apparatus further includes a firstpressure sensor disposed at an inlet of the variable-frequencycompressor and configured to detect a first pressure detecting signal,when the working mode is a refrigerating mode.

In some embodiments, the outdoor apparatus further includes a secondpressure sensor disposed at an outlet of the variable-frequencycompressor and configured to detect a second pressure detecting signal,when the working mode is a heating mode.

In some embodiments, the temperature control module is furtherconfigured to generate a current refrigerant saturation temperature byselecting one of the first pressure detecting signal and the seconddetecting signal according to the working mode and to obtain a targetrefrigerant saturation temperature, and the variable-frequency controlmodule is configured to perform the variable-frequency control on thevariable-frequency compressor according to the target refrigerantsaturation temperature and the current refrigerant saturationtemperature.

Embodiments of a third broad aspect of the present invention provide anair conditioning system. The air conditioning system includes avariable-frequency compressor; a controller configured to control thevariable-frequency compressor and comprising: a start module configuredto obtain a working mode of the air conditioning system and to start thevariable-frequency compressor according to the working mode of the aircondition; a temperature control module configured to obtain a targetrefrigerant saturation temperature, to obtain a working time of thevariable-frequency compressor and a stop-start number of time of thevariable-frequency compressor in a first predetermined period during anvariable-frequency control for the variable-frequency compressor, and toadjust the target refrigerant saturation temperature according to theworking time of the variable-frequency compressor and the stop-startnumber of time of the variable-frequency compressor in the firstpredetermined period; and a variable-frequency control module configuredto perform the variable-frequency control on the variable-frequencycompressor according to the target refrigerant saturation temperature.

In some embodiments, the temperature control module is furtherconfigured to adjust the target refrigerant saturation temperatureaccording to a predetermined step length, when the working time of thevariable-frequency compressor is larger than or equal to a first timethreshold and the stop-start number of time of the variable-frequencycompressor in the first predetermined period is larger than or equal toa first predetermined number of time threshold.

With the air conditioning system according to embodiments of the presentinvention, the variable-frequency control is performed on thevariable-frequency compressor in the outdoor apparatus by obtaining thetarget refrigerant saturation temperature. During the variable-frequencycontrol for the variable-frequency compressor, the target refrigerantsaturation temperature is adjusted according to the working time of thevariable-frequency compressor and the stop-start number of time of thevariable-frequency compressor in the first predetermined period, suchthat the variable-frequency compressor can be controlled independentfrom an indoor apparatus and without transmitting corresponding controlparameters between the indoor apparatus and the outdoor apparatus via aspecific communication, thus saving the transmission of controlparameters, reducing a complexity of the air conditioning system andimproving a reliability of the air conditioning system.

Additional aspects and advantages of embodiments of present inventionwill be given in part in the following descriptions, become apparent inpart from the following descriptions, or be learned from the practice ofthe embodiments of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and advantages of embodiments of the presentinvention will become apparent and more readily appreciated from thefollowing descriptions made with reference to the accompanying drawings,in which:

FIG. 1A is a schematic diagram of a variable-frequency air conditioningsystem in the prior art;

FIG. 1B is a schematic diagram of a variable-frequency air conditioningsystem according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a variable-frequency air conditioningsystem according to another embodiment of the present invention;

FIG. 3 is a flow chart showing a control logic of an air conditioningsystem according to a first embodiment of the present invention;

FIG. 4 is a flow chart showing a control logic of an air conditioningsystem according to a second embodiment of the present invention;

FIG. 5 is a flow chart of a method for controlling an air conditioningsystem according to an embodiment of the present invention;

FIG. 6 is a flow chart of a method for controlling an air conditioningsystem according to an embodiment of the present invention; and

FIG. 7 is a block diagram of an outdoor apparatus of an air conditioningsystem according to an embodiment of the present invention.

DETAILED DESCRIPTION

Reference will be made in detail to embodiments of the presentdisclosure. Embodiments of the present disclosure will be shown indrawings, in which the same or similar elements and the elements havingsame or similar functions are denoted by like reference numeralsthroughout the descriptions. The embodiments described herein accordingto drawings are explanatory and illustrative, not construed to limit thepresent disclosure.

The following description provides a plurality of embodiments orexamples configured to achieve different structures of the presentdisclosure. In order to simplify the publishment of the presentdisclosure, components and dispositions of the particular embodiment aredescribed in the following, which are only explanatory and not construedto limit the present disclosure. In addition, the present disclosure mayrepeat the reference number and/or letter in different embodiments forthe purpose of simplicity and clarity, and the repeat does not indicatethe relationship of the plurality of embodiments and/or dispositions.Moreover, in description of the embodiments, the structure of the secondcharacteristic “above” the first characteristic may include anembodiment formed by the first and second characteristic contacteddirectly, and also may include another embodiment formed between thefirst and the second characteristic, in which the first characteristicand the second characteristic may not contact directly.

In addition, terms such as “first” and “second” are used herein forpurposes of description and are not intended to indicate or implyrelative importance or significance. Therefore, a “first” or “second”feature may explicitly or implicitly comprise one or more features.Further, in the description, unless indicated otherwise, “a pluralityof” refers to two or more.

An air conditioning system according to embodiments of the presentinvention will be described in the following with reference to drawings.

FIG. 1B is a schematic diagram of the air conditioning system accordingto an embodiment of the present invention. As shown in FIG. 1B, the airconditioning system includes an indoor apparatus 1 and an outdoorapparatus 2.

The outdoor apparatus 2 includes a variable-frequency compressor Mc anda controller 21, and the controller 21 performs a variable-frequencycontrol on the variable-frequency compressor Mc according to operationparameters of the variable-frequency compressor Mc and independent fromthe indoor apparatus 1.

Moreover, the outdoor apparatus 2 further includes a communicator 22configured to receive an on-off instruction and a mode optioninstruction sent from a remote 3 and a line controller 4 directly orfrom the indoor apparatus 1. The controller 21 performs thevariable-frequency control on the variable-frequency compressor Mcaccording to the operation parameters of the variable-frequencycompressor Mc and a working mode corresponding to the mode optioninstruction. Specifically, as shown in FIG. 1B, the communicator 22 is asignal receiving module having a control signal receiving unit, and acontrol signal indicating the on-off instruction and a control signalindicating the mode option instruction sent from the remote 3 and theline controller 4 directly or from the indoor apparatus 1 are receivedonly by the control signal receiving unit.

As shown in FIG. 1B, the indoor apparatus 1 includes an indoor controlsignal receiving module 11, an indoor control processor 12, a signaltransmission module 13, an indoor fan 14 and an indoor throttle valve15. The indoor fan 14 and the indoor throttle valve 15 are controlled bythe indoor control processor 12, and the indoor apparatus 1 sends thecontrol signal indicating the on-off instruction and the control signalindicating the mode option instruction to the control signal receivingunit in the communicator 22 via the signal transmission module 13 withgeneral transmission rules. The control signal indicating the on-offinstruction and the control signal indicating the mode optioninstruction can be sent to the communicator 22 in the outdoor apparatus2 from the indoor apparatus 1 directly. Or, the control signalindicating the on-off instruction and the control signal indicating themode option instruction sent from the remote 3 and the line controller 4are received by the indoor control signal receiving module 11, and thenthe control signal indicating the on-off instruction and the controlsignal indicating the mode option instruction are transmitted to thecontrol signal receiving unit in the communicator 22 by the signaltransmission module 13 with general transmission rules.

In embodiments of the present invention, the air conditioning systemcontrols a start or stop and the mode option of the outdoor apparatusaccording to the control signal indicating the on-off instruction andthe control signal indicating the mode option instruction.

As shown in FIG. 1B, the outdoor apparatus 2 further includes a firstpressure sensor 23 disposed at an inlet of the variable-frequencycompressor Mc, and the first pressure sensor 23 is configured togenerate a first pressure detecting signal when a working mode of theair conditioning system is a refrigerating mode. When the airconditioning system only has refrigerating function, the first pressuresensor 23 is required to be disposed at a return-air pipe of thevariable-frequency compressor Mc to detect a pressure at a return-airlow pressure side of the variable-frequency compressor Mc when the airconditioning system is in the refrigerating mode.

In an embodiment of the present invention, as shown in FIG. 2, theoutdoor apparatus 2 further includes a second pressure sensor 24disposed at an outlet of the variable-frequency compressor Mc, and thesecond pressure sensor 24 is configured to generate a second pressuredetecting signal when the working mode is a heating mode. In otherwords, when the air conditioning system is a refrigerating and heatingair condition, the second pressure sensor 24 is further required to bedisposed at an exhaust pipe of the variable-frequency compressor Mc todetect a pressure at an exhaust high pressure side when the airconditioning system is in the heating mode. Alternatively, a pressuresensor may be disposed in rear of a four-way value, such that when theair conditioning system is in the refrigerating mode, a pressuredetected by the pressure sensor is a pressure at the low pressure sidewhich is generally equal to the pressure at the return-air low pressureside and when the air conditioning system is in the heating mode, thepressure detected by the pressure sensor is a pressure at the highpressure side which is generally equal to the pressure at the exhausthigh pressure side.

The controller 21 selects one of the first pressure detecting signal andthe second pressure detecting signal to generate a current refrigerantsaturation temperature according to the working mode of the airconditioning system, and obtains a target refrigerant saturationtemperature. Moreover, the controller 21 performs a variable-frequencycontrol on the compressor Mc according to the current refrigerantsaturation temperature and the target refrigerant saturationtemperature. During the variable-frequency control for thevariable-frequency compressor Mc, the controller 21 adjusts the targetrefrigerant saturation temperature according to operation parameters ofthe variable-frequency compressor Mc. In embodiments of the presentinvention, the controller 21 sets an adjusted target refrigerantsaturation temperature as the refrigerant saturation temperature of theoutdoor apparatus 2 in a next start, when the outdoor apparatus 2 isstopped.

As show in FIG. 1B or FIG. 2, the outdoor apparatus 2 further includes atemperature sensor 25. The temperature sensor 25 is configured to detecta current ambient temperature of the outdoor apparatus 2. If the outdoorapparatus 2 is started for a first time in a predetermined workingcycle, the controller 21 determines the target refrigerant saturationtemperature according to the current ambient temperature of the outdoorapparatus 2. It should be noted that, the predetermined working cycleshould be understood broadly and may be several years or several months.For example, the outdoor apparatus 2 is stopped in summer and isre-started in winter. When the outdoor apparatus 2 is started for thefirst time in winter, the controller 21 determines the targetrefrigerant saturation temperature according to the current ambienttemperature of the outdoor apparatus 2, instead of using the adjustedtarget refrigerant saturation temperature recorded at a last stop (i.e.,in summer several months ago).

In addition, as shown in FIG. 1B or FIG. 2, the outdoor apparatus 2further includes an outdoor fan Mf, an outdoor expansion valve Ev, anoutdoor four-way valve SV and an outdoor system protection sensor 26, asystem parameter sampling module 27 connected between respective sensorand the controller 21 and configured to process parameters sampled bythe first pressure sensor 23, the second pressure sensor 24, thetemperature sensor 25 and the outdoor system protection sensor 26 and tosend the sampled parameters to the controller 21. The controller 21includes a compressor output frequency control module 211, a fan outputcontrol module 212, an outdoor expansion valve output control module 213and an outdoor four-way valve output control module 214 which controlthe variable-frequency compressor Mc, the outdoor fan Mf, the outdoorexpansion valve Ev and the outdoor four-way valve SV respectivelyaccording to sampled signals from the system parameter sampling module27.

In an embodiment of the present invention, the operation parameters ofthe variable-frequency compressor Mc include a working time of thevariable-frequency compressor Mc and a stop-start number of time in apredetermined first period. When the working time of thevariable-frequency compressor is larger than or equal to a first timethreshold and the stop-start number of time of the variable-frequencycompressor in the first predetermined period is larger than or equal toa first predetermined number of time threshold, the controller 21adjusts the target refrigerant saturation temperature according to apredetermined step length.

Specifically, a control process of the air conditioning system will bedescribed in following two embodiments of the heating mode and therefrigerating mode respective.

Embodiment 1

As shown in FIG. 3, in the refrigerating mode, the first pressure sensor23 configured to detect the pressure at the low pressure side isdisposed in the outdoor apparatus 2. The outdoor apparatus 2 starts orstops a refrigerating system according to the control signal indicatingthe mode option instruction and the control signal indicating the on-offinstruction. The controller 21 delays a second predetermined period(such as S seconds) to start or stop after receiving the control signalindicating the on-off instruction, so as to prevent the controller 21from executing incorrect instruction caused by misoperation.

Moreover, if the indoor apparatus 1 is started for the first time in thepredetermined working cycle, the controller 21 determines the targetrefrigerant saturation temperature Tes according to the current ambienttemperature of the outdoor apparatus 2. For example, when the currentambient temperature of the outdoor apparatus 2 is between 30° C. and 35°C., an initial target refrigerant saturation temperature may be set as6° C.; when the current ambient temperature of the outdoor apparatus 2is between 35° C. and 40° C., the initial target refrigerant saturationtemperature may be set as 3° C.; when the current ambient temperature ofthe outdoor apparatus 2 is between 25° C. and 30° C., the initial targetrefrigerant saturation temperature may be set as 8° C. When the indoorapparatus 1 is not started for the first time in the predeterminedworking cycle, the recorded adjusted target refrigerant saturationtemperature in a last stop is set as the initial target refrigerantsaturation temperature of the outdoor apparatus 2 in a current start.

Subsequently, the controller 21 generates the current refrigerantsaturation temperature Te according to the first pressure detectingsignal generated by the first pressure sensor 23. And then thecontroller 21 performs a PID (Proportion Integration Differentiation)adjustment on the current refrigerant saturation temperature Teaccording to the target refrigerant saturation temperature Tes. The PIDadjustment is illustrated as follows.

A difference between the current refrigerant saturation temperature Teand the target refrigerant saturation temperature Tes is denoted asΔe=Te−Tes. For example, the current refrigerant saturation temperatureTe is 10, the target refrigerant saturation temperature Tes is 6, andthen a current difference is denoted as Δe0=10−6=4. Since sampled dataare discrete, according to a difference value of a previous Δe1 (i.e., adifference of a certain period (such as 40 s) ago) and a current Δe0 ora weighted value of the previous Δe1 and the current Δe0, feedbackquantities of Δe0 and Δe1 can be determined to perform the PIDadjustment so as to obtain an operation frequency variation of thevariable-frequency compressor. A rotating speed of thevariable-frequency compressor is equal to a sum of a current rotatingspeed and a rotating speed variation, and the rotating speed variationof the variable-frequency compressor is represented as(Kp+Ki/s+Kd*s)*E(Δe1, Δe0), where Kp, Ki, s, Kd are predeterminedconstants, and Δe1, Δe0 are real-time feedback quantities.

In the embodiment of the present invention, when the outdoor apparatus 2is stopped, the controller 21 determines a working time of thevariable-frequency compressor Mc. If the working time of thevariable-frequency compressor Mc is less than a first time threshold(such as Y minutes), this stop of the outdoor apparatus 2 is notcontributed to the stop-start number of time according to which thecontroller 21 adjusts the target refrigerant saturation temperature, soas to prevent the controller 21 from executing incorrect instructioncaused by misoperation.

If the working time of the variable-frequency compressor Mc is largerthan or equal to the first predetermined threshold (such as Y minutes),this stop of the outdoor apparatus 2 is contributed to the stop-startnumber of time according to which the controller 21 adjusts the targetrefrigerant saturation temperature. Moreover, when the stop-start numberof time of the variable-frequency compressor within a firstpredetermined period (such as X minutes) is larger than or equal to afirst predetermined number of time threshold (such as Z times), arefrigerating load of the indoor apparatus 1 is determined as relativesmall and the controller 21 adjusts the target refrigerant saturationtemperature Tes according to the predetermined step length, that is, thecontroller 21 keeps revising the target refrigerant saturationtemperature Tes upwards, for example the current refrigerant saturationtemperature Tes is updated as Tes=Tes+1. Simultaneously, the workingtime of the variable-frequency compressor Mc returns to 0 and is retimedfrom this moment, and an updated target refrigerant saturationtemperature Tes is used to perform the PID adjustment on the currentrefrigerant saturation temperature Te constantly. And thus thevariable-frequency compressor may lower its rotating speed so as toreduce a refrigerating capacity, such that an indoor temperature isdecreased slowly and a frequent stop of the outdoor apparatus 2 isreduced. Simultaneously, the current target refrigerant saturationtemperature is recorded as the initial target refrigerant saturationtemperature of the next start.

Thus, the air conditioning system according to embodiments of thepresent invention makes an identification and determination according toinfluence of indoor loads on operation parameters of the refrigeratingsystem so as to adjust the operation frequency of the variable-frequencycompressor intelligently.

Embodiment 2

As shown in FIG. 4, in the heating mode, the second pressure sensor 24configured to detect the pressure at the high pressure side is disposedin the outdoor apparatus 2. The outdoor apparatus 2 starts or stops aheating system according to the control signal indicating the modeoption instruction and the control signal indicating the on-offinstruction. The controller 21 delays a second predetermined period(such as S seconds) to start or stop after receiving the control signalindicating the on-off instruction, so as to prevent the controller 21from executing incorrect instruction caused by misoperation.

Moreover, if the indoor apparatus 1 is started for the first time in thepredetermined working cycle, the controller 21 determines the targetrefrigerant saturation temperature Tcs according to the current ambienttemperature of the outdoor apparatus 2. For example, when the currentambient temperature of the outdoor apparatus 2 is between 7° C. and 10°C., the initial target refrigerant saturation temperature is determinedas 46° C. When the indoor apparatus 1 is not started for the first timein the predetermined working cycle, the recorded adjusted targetrefrigerant saturation temperature in the last stop is set as theinitial target refrigerant saturation temperature of the outdoorapparatus 2 in the current start.

Subsequently, the controller 21 generates the current refrigerantsaturation temperature Tc according to the second pressure detectingsignal generated by the second pressure sensor 24. And then thecontroller 21 performs the PID adjustment on the current refrigerantsaturation temperature Tc according to the target refrigerant saturationtemperature Tcs.

In the embodiment of the present invention, when the outdoor apparatus 2is stopped, the controller 21 determines the working time of thevariable-frequency compressor Mc. If the working time of thevariable-frequency compressor Mc is less than the first time threshold(such as Y minutes), this stop of the outdoor apparatus 2 is notcontributed to the stop-start number of time according to which thecontroller 21 adjusts the target refrigerant saturation temperature, soas to prevent the controller 21 from executing incorrect instructioncaused by misoperation.

If the working time of the variable-frequency compressor Mc is largerthan or equal to the first predetermined threshold (such as Y minutes),this stop of the outdoor apparatus 2 is contributed to the stop-startnumber of time according to which the controller 21 adjusts the targetrefrigerant saturation temperature. Moreover, when the stop-start numberof time of the variable-frequency compressor within a firstpredetermined period (such as X minutes) is larger than or equal to afirst predetermined number of time threshold (such as Z times), aheating load of the indoor apparatus 1 is determined as relative smalland the controller 21 adjusts the target refrigerant saturationtemperature Tcs according to the predetermined step length, that is, thecontroller 21 keeps revising the target refrigerant saturationtemperature Tcs downwards, for example the current refrigerantsaturation temperature Tcs is updated as Tcs=Tcs−1. Simultaneously, theworking time of the variable-frequency compressor Mc returns to 0 and isretimed from this moment, and an updated target refrigerant saturationtemperature Tcs is used to perform the PID adjustment on the currentrefrigerant saturation temperature Tc constantly. And thus thevariable-frequency compressor may lower its rotating speed so as toreduce a refrigerating capacity, such that an indoor temperature isdecreased slowly and a frequent stop of the outdoor apparatus 2 isreduced. Simultaneously, the current target refrigerant saturationtemperature is recorded as the initial target refrigerant saturationtemperature of the next start.

Thus, the air conditioning system according to embodiments of thepresent invention makes an identification and determination according toinfluence of indoor loads on operation parameters of the refrigeratingsystem so as to adjust the operation frequency of the variable-frequencycompressor intelligently.

In embodiments of the present invention, the air conditioning system mayhave a plurality of loads or a single load, and may only haverefrigerating function or have both refrigerating and heating functions.The indoor apparatus does not transmit parameters (such as the indoorambient temperature) to the outdoor apparatus, and the outdoor apparatusis controlled to start or stop according to the on-off instruction sentfrom the remote, the line controller or the indoor apparatus. With theair conditioning system according to embodiments of the presentinvention, the variable-frequency compressor may be controlled withoutparameter communication between the indoor apparatus and the outdoorapparatus. The controller of the outdoor apparatus may learnindependently how to control the variable-frequency compressor andcompletes controlling the variable-frequency compressor and otherelectrical components of the outdoor apparatus, such that the indoortemperature can reach and maintain a predetermined temperature.

According to embodiments of the present invention, The controller 21delays a second predetermined period (such as S seconds) to start orstop after receiving the control signal indicating the on-offinstruction, so as to prevent the controller 21 from executing incorrectinstruction caused by misoperation.

With the air conditioning system according to embodiments of the presentinvention, the controller of the outdoor apparatus performs thevariable-frequency control on the variable-frequency compressoraccording to the operation parameters of the variable-frequencycompressor, independent from the indoor apparatus and without parametercommunication between the indoor apparatus and the outdoor apparatus,such that the structure of the air conditioning system is simplified andthe cost is greatly reduced.

A method for controlling an air conditioning system according toembodiments of the present invention is described in the following withreference to the drawings.

FIG. 5 is a flow char of a method for controlling an air conditioningsystem. As shown in FIG. 5, the method for controlling the airconditioning system includes following steps.

At step S1, operation parameters of a variable-frequency compressor inan outdoor apparatus of the air conditioning system are obtained.

At step S2, the variable-frequency compressor in the outdoor apparatusis controlled by a controller of the outdoor apparatus according tooperation parameters of the variable-frequency compressor andindependent from an indoor apparatus of the air conditioning system.

In other words, after the air conditioning system is started, a firstpressure sensor and/or a second pressure sensor of the outdoor apparatusdetects the pressure at a return-air low pressure (i.e., admittancepressure) and/or an exhaust high pressure, and a temperature sensordetects the current ambient temperature of the outdoor apparatus, andthen the detected admittance pressure and/or exhaust high pressure andthe detected current ambient temperature of the outdoor apparatus aretransmitted to a system parameter sampling module. The controllergenerates control signals according to these detected parameters so asto perform a variable-frequency control on the variable-frequencycompressor and to perform corresponding controls on an outdoor fan, anoutdoor expansion valve and an outdoor four-way valve respectively.

With the method for controlling the air conditioning system according toembodiments of the present invention, the controller of the outdoorapparatus performs the variable-frequency control on thevariable-frequency compressor according to the operation parameters ofthe variable-frequency compressor, independent from the indoorapparatus, and without transmitting parameters between the indoorapparatus and the outdoor apparatus via specific communication, suchthat the transmission of control parameters is saved, a complexity ofthe air conditioning system is reduced and an operation reliability ofthe air conditioning system is improved.

Further, as shown in FIG. 6, the method according to an embodiment ofthe present invention includes following steps.

At step S801, a working mode of the air conditioning system is obtainedand a variable-frequency compressor in an outdoor apparatus of the airconditioning system is started according to the working mode.

In one embodiment, an on-off instruction and a mode option instructionsent from a remote, a line controller or the indoor apparatus of the airconditioning system are received via a communicator in the outdoorapparatus, such that the working mode of the air conditioning system canbe obtained.

At step 802, a target refrigerant saturation temperature is obtained.

In an embodiment, if the outdoor apparatus is started for the first timein a predetermined working cycle, a current ambient temperature of theoutdoor apparatus is detected and a target refrigerant saturationtemperature is determined according to the current ambient temperatureof the outdoor apparatus. It should be noted that, the predeterminedworking cycle should be understood broadly and may be several years orseveral months. For example, the outdoor apparatus is stopped in summerand is re-started in winter. When the outdoor apparatus is started forthe first time in winter, the controller determines the targetrefrigerant saturation temperature according to the current ambienttemperature of the outdoor apparatus, instead of using the adjustedtarget refrigerant saturation temperature recorded at a last stop (i.e.,in summer several months ago).

At step S803, a variable-frequency control is performed on thevariable-frequency compressor according to the target refrigerantsaturation temperature.

At step S804, during the variable-frequency control, a working time ofthe variable-frequency compressor and a stop-start number of time of thevariable-frequency compressor in a first predetermined period areobtained.

At step S805, the target refrigerant saturation temperature is adjustedaccording to the working time of the variable-frequency compressor andthe stop-start number of time of the variable-frequency compressor inthe first predetermined time.

At the step S805, the target refrigerant saturation temperature isadjusted according to the working time of the variable-frequencycompressor and the stop-start number of time of the variable-frequencycompressor in the first predetermined time as follows. First, it isdetermined whether the working time of the variable-frequency compressoris larger than or equal to a first time threshold; if yes, thestop-start number of time of the variable-frequency compressor in thefirst predetermined period is obtained; and if the stop-start number oftime of the variable-frequency compressor in the first predeterminedperiod is larger than or equal to the first predetermined number of timethreshold, the target refrigerant saturation temperature is adjustedaccording to a predetermined step length.

Specifically, when the working mode is a heating mode, the targetrefrigerant saturation temperature is reduced by the predetermined steplength and the working time of the variable-frequency compressor returnsto zero; when the working mode is a refrigerating mode, the targetrefrigerant saturation temperature is increased by the predeterminedstep length and the working time of the variable-frequency compressorreturns to zero.

The method for controlling the air conditioning system according toembodiments of the present invention will be described in details withreference to an embodiment lof the refrigerating mode and an embodiment2 of the heating mode.

Embodiment 1

As shown in FIG. 3, in the refrigerating mode, the first pressure sensor23 configured to detect the pressure at the low pressure side isdisposed in the outdoor apparatus 2. The outdoor apparatus 2 starts orstops a refrigerating system thereof according to the control signalindicating the mode option instruction and the control signal indicatingthe on-off instruction. The controller 21 delays a second predeterminedperiod (such as S seconds) to start or stop after receiving the controlsignal indicating the on-off instruction, so as to prevent thecontroller 21 from executing incorrect instruction caused bymisoperation.

Moreover, if the indoor apparatus 1 is started for the first time in thepredetermined working cycle, the controller 21 determines the targetrefrigerant saturation temperature Tes according to the current ambienttemperature of the outdoor apparatus 2. For example, when the currentambient temperature of the outdoor apparatus 2 is between 30° C. and 35°C., an initial target refrigerant saturation temperature may be set as6° C.; when the current ambient temperature of the outdoor apparatus 2is between 35° C. and 40° C., the initial target refrigerant saturationtemperature may be set as 3° C.; when the current ambient temperature ofthe outdoor apparatus 2 is between 25° C. and 30° C., the initial targetrefrigerant saturation temperature may be set as 8° C. When the indoorapparatus 1 is not started for the first time in the predeterminedworking cycle, the recorded adjusted target refrigerant saturationtemperature in a last stop is set as the initial target refrigerantsaturation temperature of the outdoor apparatus 2 in a current start.

Subsequently, the controller 21 generates the current refrigerantsaturation temperature Te according to the first pressure detectingsignal generated by the first pressure sensor 23. And then thecontroller 21 performs a PID (Proportion Integration Differentiation)adjustment on the current refrigerant saturation temperature Teaccording to the target refrigerant saturation temperature Tes. The PIDadjustment is illustrated as follows.

A difference between the current refrigerant saturation temperature Teand the target refrigerant saturation temperature Tes is denoted asΔe=Te−Tes. For example, the current refrigerant saturation temperatureTe is 10, the target refrigerant saturation temperature Tes is 6, andthen a current difference is denoted as Δe0=10−6=4. Since sampled dataare discrete, according to a difference value of a previous Δe1 (i.e., adifference of a certain period (such as 40 s) ago) and a current Δe0 ora weighted value of the previous Δe1 and the current Δe0, feedbackquantities of Δe0 and Δe1 can be determined to perform the PIDadjustment so as to obtain an operation frequency variation of thevariable-frequency compressor. A rotating speed of thevariable-frequency compressor is equal to a sum of a current rotatingspeed and a rotating speed variation, and the rotating speed variationof the variable-frequency compressor is represented as(Kp+Ki/s+Kd*s)*E(Δe1, Δe0), where Kp, Ki, s, Kd are predeterminedconstants, and Δe1, Δe0 are real-time feedback quantities.

In the embodiment of the present invention, when the outdoor apparatus 2is stopped, the controller 21 determines a working time of thevariable-frequency compressor Mc. If the working time of thevariable-frequency compressor Mc is less than a first time threshold(such as Y minutes), this stop of the outdoor apparatus 2 is notcontributed to the stop-start number of time according to which thecontroller 21 adjusts the target refrigerant saturation temperature, soas to prevent the controller 21 from executing incorrect instructioncaused by misoperation.

If the working time of the variable-frequency compressor Mc is largerthan or equal to the first predetermined threshold (such as Y minutes),this stop of the outdoor apparatus 2 is contributed to the stop-startnumber of time according to which the controller 21 adjusts the targetrefrigerant saturation temperature. Moreover, when the stop-start numberof time of the variable-frequency compressor within a firstpredetermined period (such as X minutes) is larger than or equal to afirst predetermined number of time threshold (such as Z times), arefrigerating load of the indoor apparatus 1 is determined as relativesmall and the controller 21 adjusts the target refrigerant saturationtemperature Tes according to the predetermined step length, that is, thecontroller 21 keeps revising the target refrigerant saturationtemperature Tes upwards, for example the current refrigerant saturationtemperature Tes is updated as Tes=Tes+1. Simultaneously, the workingtime of the variable-frequency compressor Mc returns to 0 and is retimedfrom this moment, and an updated target refrigerant saturationtemperature Tes is used to perform the PID adjustment on the currentrefrigerant saturation temperature Te constantly. And thus thevariable-frequency compressor may lower its rotating speed so as toreduce a refrigerating capacity, such that an indoor temperature isdecreased slowly and a frequent stop of the outdoor apparatus 2 isreduced. Simultaneously, the current target refrigerant saturationtemperature is recorded as the initial target refrigerant saturationtemperature of the next start.

Thus, the method for controlling the air conditioning system accordingto embodiments of the present invention makes an identification anddetermination according to influence of indoor loads on operationparameters of the refrigerating system so as to adjust the operationfrequency of the variable-frequency compressor intelligently.

Embodiment 2

As shown in FIG. 4, in the heating mode, the second pressure sensor 24configured to detect the pressure at the high pressure side is disposedin the outdoor apparatus 2. The outdoor apparatus 2 starts or stops aheating system according to the control signal indicating the modeoption instruction and the control signal indicating the on-offinstruction. The controller 21 delays a second predetermined period(such as S seconds) to start or stop after receiving the control signalindicating the on-off instruction, so as to prevent the controller 21from executing incorrect instruction caused by misoperation.

Moreover, if the indoor apparatus 1 is started for the first time in thepredetermined working cycle, the controller 21 determines the targetrefrigerant saturation temperature Tcs according to the current ambienttemperature of the outdoor apparatus 2. For example, when the currentambient temperature of the outdoor apparatus 2 is between 7° C. and 10°C., the initial target refrigerant saturation temperature is determinedas 46° C. When the indoor apparatus 1 is not started for the first timein the predetermined working cycle, the recorded adjusted targetrefrigerant saturation temperature in the last stop is set as theinitial target refrigerant saturation temperature of the outdoorapparatus 2 in the current start.

Subsequently, the controller 21 generates the current refrigerantsaturation temperature Tc according to the second pressure detectingsignal generated by the second pressure sensor 24. And then thecontroller 21 performs the PID adjustment on the current refrigerantsaturation temperature Tc according to the target refrigerant saturationtemperature Tcs.

In the embodiment of the present invention, when the outdoor apparatus 2is stopped, the controller 21 determines the working time of thevariable-frequency compressor Mc. If the working time of thevariable-frequency compressor Mc is less than the first time threshold(such as Y minutes), this stop of the outdoor apparatus 2 is notcontributed to the stop-start number of time according to which thecontroller 21 adjusts the target refrigerant saturation temperature, soas to prevent the controller 21 from executing incorrect instructioncaused by misoperation.

If the working time of the variable-frequency compressor Mc is largerthan or equal to the first predetermined threshold (such as Y minutes),this stop of the outdoor apparatus 2 is contributed to the stop-startnumber of time according to which the controller 21 adjusts the targetrefrigerant saturation temperature. Moreover, when the stop-start numberof time of the variable-frequency compressor within a firstpredetermined period (such as X minutes) is larger than or equal to afirst predetermined number of time threshold (such as Z times), aheating load of the indoor apparatus 1 is determined as relative smalland the controller 21 adjusts the target refrigerant saturationtemperature Tcs according to the predetermined step length, that is, thecontroller 21 keeps revising the target refrigerant saturationtemperature Tcs downwards, for example the current refrigerantsaturation temperature Tcs is updated as Tcs=Tcs−1. Simultaneously, theworking time of the variable-frequency compressor Mc returns to 0 and isretimed from this moment, and an updated target refrigerant saturationtemperature Tcs is used to perform the PID adjustment on the currentrefrigerant saturation temperature Tc constantly. And thus thevariable-frequency compressor may lower its rotating speed so as toreduce a refrigerating capacity, such that an indoor temperature isdecreased slowly and a frequent stop of the outdoor apparatus 2 isreduced. Simultaneously, the current target refrigerant saturationtemperature is recorded as the initial target refrigerant saturationtemperature of the next start.

Thus, the method for controlling the air conditioning system accordingto embodiments of the present invention makes an identification anddetermination according to influence of indoor loads on operationparameters of the refrigerating system so as to adjust the operationfrequency of the variable-frequency compressor intelligently.

In an embodiment of the present invention, when the working mode is therefrigerating mode, a first pressure detecting signal is obtained by afirst pressure sensor disposed at an inlet of the variable-frequencycompressor. In other words, when the air conditioning system is arefrigerating-only air condition, in order to detect a pressure at areturn-air low pressure side of the variable-frequency compressor duringthe refrigeration of the air conditioning system, only the firstpressure sensor is required to be disposed at a return-air pipe of thevariable-frequency compressor.

In another embodiment of the present invention, when the working mode isthe heating mode, a second pressure detecting signal can be detected bya second pressure sensor disposed at an outlet of the variable-frequencycompressor. In other words, when the air conditioning system is arefrigerating and heating air condition, in order to detect the pressureat an exhaust high pressure side of the variable-frequency compressorduring the heating of the air conditioning system, the second pressuresensor is further required to be disposed at an exhaust pipe of thevariable-frequency compressor. Alternatively, a pressure sensor may bedisposed in rear of a four-way value. When the air conditioning systemis in the refrigerating mode, the pressure detected by the pressuresensor which is the pressure at the low pressure side is generally equalto the return-air low pressure; when the air conditioning system is inthe heating mode, the pressure detected by the pressure sensor which isthe pressure at the high pressure side is generally equal to the exhausthigh pressure.

In one embodiment, step S803 may further comprise following steps.

At step S11, a current refrigerant saturation temperature is generatedby selecting one of the first pressure detecting signal and the secondpressure detecting signal according to the working mode.

At step S12, the variable-frequency control is performed on thevariable-frequency compressor according to the target refrigerantsaturation temperature and the current refrigerant saturationtemperature.

In an embodiment of the present invention, the method for controllingthe air conditioning system further includes: an adjusted targetrefrigerant saturation temperature is set as the refrigerant saturationtemperature of the outdoor apparatus in a next start, when the outdoorapparatus is stopped.

In an embodiment of the present invention, when receiving the controlsignal indicating the on-off instruction, the controller delays a secondpredetermined period (such as S seconds) to start or stop, so as toprevent the controller from executing incorrect instruction caused bymisoperation.

With the method for controlling the air conditioning system according toembodiments of the present invention, the variable-frequency control isperformed on the variable-frequency compressor in the outdoor apparatusby obtaining the target refrigerant saturation temperature. During thevariable-frequency control for the variable-frequency compressor, thetarget refrigerant saturation temperature is adjusted according to theworking time of the variable-frequency compressor and the stop-startnumber of time of the variable-frequency compressor in the firstpredetermined period, such that the variable-frequency compressor can becontrolled independent from the indoor apparatus and withouttransmitting corresponding control parameters between the indoorapparatus and the outdoor apparatus via a specific communication, thussaving the transmission of control parameters, reducing a complexity ofthe air conditioning system and improving a reliability of the airconditioning system.

An outdoor apparatus of an air conditioning system according toembodiments of the present invention will be described in the followingwith reference to the drawings.

FIG. 7 is a block diagram of an outdoor apparatus of an air conditioningsystem according to an embodiment of the present invention. As shown inFIG. 7, the outdoor apparatus 2 includes a variable-frequency compressorMc and a controller 21.

The controller 21 is configured to control the variable-frequencycompressor Mc and includes: a start module 201, a temperature controlmodule 202 and a variable-frequency control module 203 (i.e., acompressor output frequency control module 211 shown in FIG. 1B or 2).

The start module 201 is configured to obtain a working mode of the airconditioning system and to start the variable-frequency compressor Mcaccording to the working mode of the air conditioner. The temperaturecontrol module 202 is configured to obtain an initial target refrigerantsaturation temperature and to adjust a target refrigerant saturationtemperature according to operation parameters of the variable-frequencycompressor Mc during the variable-frequency control for thevariable-frequency compressor Mc. Furthermore, during thevariable-frequency control, the temperature control module 202 isconfigured to obtain a working time of the variable-frequency compressorMc and a stop-start number of time of the variable-frequency compressorMc in a first predetermined period, and to adjust the target refrigerantsaturation temperature according to the working time of thevariable-frequency compressor MC and the stop-start number of time ofthe variable-frequency compressor Mc in the first predetermined period.The variable-frequency control module 203 (i.e., the compressor outputfrequency control module 211) is configured to perform thevariable-frequency control on the variable-frequency compressor Mcaccording to the target refrigerant saturation temperature.

In an embodiment of the present invention, the temperature controlmodule 202 is further configured to set an adjusted target refrigerantsaturation temperature as the refrigerant saturation temperature of theoutdoor apparatus 2 in a next start, when the outdoor apparatus 2 isstopped.

As shown in FIG. 1B, the outdoor apparatus 2 further includes a firstpressure sensor 23 disposed at an inlet of the variable-frequencycompressor Mc, and the first pressure sensor 23 is configured togenerate a first pressure detecting signal when a working mode of theair conditioning system is a refrigerating mode. When the airconditioning system only has a refrigerating function, only the firstpressure sensor 23 is required to be disposed at a return-air pipe ofthe variable-frequency compressor Mc to detect a pressure at areturn-air low pressure side of the variable-frequency compressor Mcwhen the air conditioning system is in the refrigerating mode.

In an embodiment of the present invention, as shown in FIG. 2, theoutdoor apparatus 2 further includes a second pressure sensor disposedat an outlet of the variable-frequency compressor Mc, and the secondpressure sensor 24 is configured to generate a second pressure detectingsignal when the working mode is a heating mode. In other words, when theair conditioning system is a refrigerating and heating air condition,the second pressure sensor 24 is further required to be disposed at anexhaust pipe of the variable-frequency compressor Mc to detect apressure at an exhaust high pressure side when the air conditioningsystem is in the heating mode. Alternatively, a pressure sensor may bedisposed in rear of a four-way value, such that when the airconditioning system is in the refrigerating mode, a pressure detected bythe pressure sensor is a pressure at the low pressure side which isgenerally equal to the pressure at the return-air low pressure side andwhen the air conditioning system is in the heating mode, the pressuredetected by the pressure sensor is a pressure at the high pressure sidewhich is generally equal to the pressure at the exhaust high pressureside.

The temperature control module 202 is further configured to generate acurrent refrigerant saturation temperature by selecting one of the firstpressure detecting signal and the second detecting signal according tothe working mode, to obtain a target refrigerant saturation temperatureand to perform the variable-frequency control on the variable-frequencycompressor Mc according to the target refrigerant saturation temperatureand the current refrigerant saturation temperature.

As shown in FIG. 1B or FIG. 2, the outdoor apparatus 2 further includesa temperature sensor 25. The temperature sensor 25 is further configuredto detect the current ambient temperature of the outdoor apparatus 2. Ifthe outdoor apparatus 2 is started for the first time in thepredetermined working cycle, the temperature control module 202determines the target refrigerant saturation temperature according tothe current ambient temperature of the outdoor apparatus 2. It should benoted that, the predetermined working cycle should be understood broadlyand may be several years or several months. For example, the outdoorapparatus 2 is stopped in summer and is re-started in winter. When theoutdoor apparatus 2 is started for the first time in winter, thecontroller 21 determines the target refrigerant saturation temperatureaccording to the current ambient temperature of the outdoor apparatus 2,instead of using the adjusted target refrigerant saturation temperaturerecorded at a last stop (i.e., in summer several months ago).

In an embodiment of the present invention, the temperature controlmodule 202 is further configured to adjust the target refrigerantsaturation temperature according to the predetermined step length, whenthe working time of the variable-frequency compressor is larger than orequal to a first time threshold and the stop-start number of time of thevariable-frequency compressor in the first predetermined period islarger than or equal to a first predetermined number of time threshold.

In the embodiment, when the working mode is the heating mode, thetemperature control module 202 reduces the target refrigerant saturationtemperature by the predetermined step length and returns the workingtime of the variable-frequency compressor to zero; when the working modeis the refrigerating mode, the temperature control module 202 increasesthe target refrigerant saturation temperature by the predetermined steplength and returns the working time of the variable-frequency compressorto zero.

Specifically, as shown in FIG. 3, in the refrigerating mode, the firstpressure sensor 23 configured to detect the pressure at the low pressureside is disposed in the outdoor apparatus 2. The start module 201 startsor stops the refrigerating system according to the control signalindicating the mode option instruction and the control signal indicatingthe on-off instruction. The start module 201 delays a secondpredetermined period (such as S seconds) to start or stop afterreceiving the control signal indicating the on-off instruction, so as toprevent the controller 21 from executing incorrect instruction caused bymisoperation.

Moreover, if the indoor apparatus 1 is started for the first time in thepredetermined working cycle, the temperature control module 202determines the target refrigerant saturation temperature Tes accordingto the current ambient temperature of the outdoor apparatus 2. Forexample, when the current ambient temperature of the outdoor apparatus 2is between 30° C. and 35° C., the initial target refrigerant saturationtemperature may be set as 6° C.; when the current ambient temperature ofthe outdoor apparatus 2 is between 35° C. and 40° C., the initial targetrefrigerant saturation temperature may be set as 3° C.; when the currentambient temperature of the outdoor apparatus 2 is between 25° C. and 30°C., the initial target refrigerant saturation temperature may be set as8° C. When the indoor apparatus 1 is not started for the first time inthe predetermined working cycle, the temperature control module 202 setsthe adjusted target refrigerant saturation temperature recorded in alast stop as the initial target refrigerant saturation temperature ofthe outdoor apparatus 2 in a current start.

Subsequently, the temperature control module 202 generates the currentrefrigerant saturation temperature Te according to the first pressuredetecting signal generated by the first pressure sensor 23. And then thevariable-frequency control module 203 performs the PID adjustment on thecurrent refrigerant saturation temperature Te continuously according tothe target refrigerant saturation temperature Tes. The PID adjustment isillustrated as follows.

A difference between the current refrigerant saturation temperature Teand the target refrigerant saturation temperature Tes is denoted asΔe=Te−Tes. For example, the current refrigerant saturation temperatureTe is 10, the target refrigerant saturation temperature Tes is 6, andthen a current difference is denoted as Δe0=10−6=4. Since sampled dataare discrete, according to a difference value of a previous Δe1 (i.e., adifference of a certain period (such as 40 s) ago) and a current Δe0 ora weighted value of the previous Δe1 and the current Δe0, feedbackquantities of Δe0 and Δe1 can be determined to perform the PIDadjustment so as to obtain an operation frequency variation of thevariable-frequency compressor. A rotating speed of thevariable-frequency compressor is equal to a sum of a current rotatingspeed and a rotating speed variation, and the rotating speed variationof the variable-frequency compressor is represented as(Kp+Ki/s+Kd*s)*E(Δe1, Δe0), where Kp, Ki, s, Kd are predeterminedconstants, and Δe1, Δe0 are real-time feedback quantities.

In the embodiment of the present invention, when the outdoor apparatus 2is stopped, the temperature control module 202 determines the workingtime of the variable-frequency compressor Mc. If the working time of thevariable-frequency compressor Mc is less than a first time threshold(such as Y minutes), this stop of the outdoor apparatus 2 is notcontributed to the stop-start number of time according to which thetemperature control module 202 adjusts the target refrigerant saturationtemperature, so as to prevent the controller 21 from executing incorrectinstruction caused by misoperation.

If the working time of the variable-frequency compressor Mc is largerthan or equal to the first predetermined threshold (such as Y minutes),this stop of the outdoor apparatus 2 is contributed to the stop-startnumber of time according to which the temperature control module 202adjusts the target refrigerant saturation temperature. Moreover, whenthe stop-start number of time of the variable-frequency compressorwithin a first predetermined period (such as X minutes) is larger thanor equal to a first predetermined number of time threshold (such as Ztimes), a refrigerating load of the indoor apparatus 1 is determined asrelative small and the temperature control module 202 adjusts the targetrefrigerant saturation temperature Tes according to the predeterminedstep length, that is, the temperature control module 202 keeps revisingthe target refrigerant saturation temperature Tes upwards, for examplethe current refrigerant saturation temperature Tes is updated asTes=Tes+1. Simultaneously, the working time of the variable-frequencycompressor Mc returns to 0 and is retimed from this moment, and anupdated target refrigerant saturation temperature Tes is used to performthe PID adjustment on the current refrigerant saturation temperature Teconstantly. And thus the variable-frequency control module 203 controlthe variable-frequency compressor to lower a rotating speed thereof soas to reduce a refrigerating capacity, such that an indoor temperatureis decreased slowly and a frequent stop of the outdoor apparatus 2 isreduced. Simultaneously, the current target refrigerant saturationtemperature is recorded by the temperature control module 202 as theinitial target refrigerant saturation temperature of the next start.

Thus, the outdoor apparatus of the air conditioning system according toembodiments of the present invention makes an identification anddetermination according to influence of indoor loads on operationparameters of the refrigerating system so as to adjust the operationfrequency of the variable-frequency compressor intelligently.

In another embodiment of the present invention, as shown in FIG. 4, aprocess for adjusting the target refrigerant saturation temperature inthe heating mode by the temperature control module 202, which is similarto the process for adjusting the target refrigerant saturationtemperature in the refrigerating mode described above, will not bedescribed herein for purpose of conciseness.

With the outdoor apparatus of the air conditioning system, thevariable-frequency control is performed on the variable-frequencycompressor in the outdoor apparatus by obtaining the target refrigerantsaturation temperature. During the variable-frequency control for thevariable-frequency compressor, the target refrigerant saturationtemperature is adjusted according to the working time of thevariable-frequency compressor and the stop-start number of time of thevariable-frequency compressor in the first predetermined period, suchthat the variable-frequency compressor can be controlled independentfrom an indoor apparatus and without transmitting corresponding controlparameters between the indoor apparatus and the outdoor apparatus via aspecific communication, thus saving the transmission of controlparameters, reducing a complexity of the air conditioning system andimproving a reliability of the air conditioning system.

Any procedure or method described in the flow charts or described in anyother way herein may be understood to comprise one or more modules,portions or parts for storing executable codes that realize particularlogic functions or procedures. Moreover, advantageous embodiments of thepresent disclosure comprises other implementations in which the order ofexecution is different from that which is depicted or discussed,including executing functions in a substantially simultaneous manner orin an opposite order according to the related functions. This should beunderstood by those skilled in the art which embodiments of the presentdisclosure belong to.

The logic and/or step described in other manners herein or shown in theflow chart, for example, a particular sequence table of executableinstructions for realizing the logical function, may be specificallyachieved in any computer readable medium to be used by the instructionexecution system, device or equipment (such as the system based oncomputers, the system comprising processors or other systems capable ofobtaining the instruction from the instruction execution system, deviceand equipment and executing the instruction), or to be used incombination with the instruction execution system, device and equipment.As to the specification, “the computer readable medium” may be anydevice adaptive for including, storing, communicating, propagating ortransferring programs to be used by or in combination with theinstruction execution system, device or equipment. More specificexamples of the computer readable medium comprise but are not limitedto: an electronic connection (an electronic device) with one or morewires, a portable computer enclosure (a magnetic device), a randomaccess memory (RAM), a read only memory (ROM), an erasable programmableread-only memory (EPROM or a flash memory), an optical fiber device anda portable compact disk read-only memory (CDROM). In addition, thecomputer readable medium may even be a paper or other appropriate mediumcapable of printing programs thereon, this is because, for example, thepaper or other appropriate medium may be optically scanned and thenedited, decrypted or processed with other appropriate methods whennecessary to obtain the programs in a electric manner, and then theprograms may be stored in the computer memories.

It is understood that each part of the present disclosure may berealized by the hardware, software, firmware or their combination. Inthe above embodiments, a plurality of steps or methods may be realizedby the software or firmware stored in the memory and executed by theappropriate instruction execution system. For example, if it is realizedby the hardware, likewise in another embodiment, the steps or methodsmay be realized by one or a combination of the following techniquesknown in the art: a discrete logic circuit having a logic gate circuitfor realizing a logic function of a data signal, an application-specificintegrated circuit having an appropriate combination logic gate circuit,a programmable gate array (PGA), a field programmable gate array (FPGA),etc.

Those skilled in the art shall understand that all or parts of the stepsin the above exemplifying method of the present disclosure may beachieved by commanding the related hardware with programs. The programsmay be stored in a computer readable storage medium, and the programscomprise one or a combination of the steps in the method embodiments ofthe present disclosure when run on a computer.

In addition, each function cell of the embodiments of the presentdisclosure may be integrated in a processing module, or these cells maybe separate physical existence, or two or more cells are integrated in aprocessing module. The integrated module may be realized in a form ofhardware or in a form of software function modules. When the integratedmodule is realized in a form of software function module and is sold orused as a standalone product, the integrated module may be stored in acomputer readable storage medium.

The storage medium mentioned above may be read-only memories, magneticdisks or CD, etc.

Reference throughout this specification to “an embodiment,” “someembodiments,” “an example,” “a specific example,” or “some examples,”means that a particular feature, structure, material, or characteristicdescribed in connection with the embodiment or example is included in atleast one embodiment or example of the present disclosure. Theappearances of the phrases throughout this specification are notnecessarily referring to the same embodiment or example of the presentdisclosure. Furthermore, the particular features, structures, materials,or characteristics may be combined in any suitable manner in one or moreembodiments or examples.

Although explanatory embodiments have been shown and described, it wouldbe appreciated by those skilled in the art that the above embodimentscannot be construed to limit the present disclosure, and changes,alternatives, and modifications can be made in the embodiments withoutdeparting from spirit, principles and scope of the present disclosure.

What is claimed is:
 1. A method for controlling an air conditioningsystem, comprising: obtaining a working mode of the air conditioningsystem and starting a variable-frequency compressor in an outdoorapparatus of the air conditioning system according to the working mode;obtaining a target refrigerant saturation temperature; performing avariable-frequency control on the variable-frequency compressoraccording to the target refrigerant saturation temperature; during thevariable-frequency control, obtaining a working time of thevariable-frequency compressor and a stop-start number of time of thevariable-frequency compressor in a first predetermined period; andadjusting the target refrigerant saturation temperature according to theworking time of the variable-frequency compressor and the stop-startnumber of time of the variable-frequency compressor in the firstpredetermined time.
 2. The method according to claim 1, whereinobtaining a working mode of the air conditioning system comprisesreceiving an on-off instruction and a mode option instruction sent froma remote, a line controller or an indoor apparatus of the airconditioning system via a communicator in the outdoor apparatus.
 3. Themethod according to claim 1, further comprising: setting an adjustedtarget refrigerant saturation temperature as the refrigerant saturationtemperature of the outdoor apparatus in a next start, when the outdoorapparatus is stopped.
 4. The method according to claim 1, whereinadjusting the target refrigerant saturation temperature according to theworking time of the variable-frequency compressor and the stop-startnumber of time of the variable-frequency compressor in the firstpredetermined time comprises: determining whether the working time ofthe variable-frequency compressor is larger than or equal to a firsttime threshold; if yes, obtaining the stop-start number of time of thevariable-frequency compressor in the first predetermined period; and ifthe stop-start number of time of the variable-frequency compressor inthe first predetermined period is larger than or equal to a firstpredetermined number of time threshold, adjusting the target refrigerantsaturation temperature according to a predetermined step length.
 5. Themethod according to claim 4, wherein when the working mode is a heatingmode, the target refrigerant saturation temperature is reduced by thepredetermined step length and the working time of the variable-frequencycompressor returns to zero; when the working mode is a refrigeratingmode, the target refrigerant saturation temperature is increased by thepredetermined step length and the working time of the variable-frequencycompressor returns to zero.
 6. The method according to claim 1, whereinobtaining a target refrigerant saturation temperature comprises:detecting a current ambient temperature of the outdoor apparatus, whenthe outdoor apparatus is started for a first time in a predeterminedworking cycle; and determining the target refrigerant saturationtemperature according to the current ambient temperature of the outdoorapparatus.
 7. The method according to claim 1, wherein a first pressuredetecting signal is detected via a first pressure sensor disposed at aninlet of the variable-frequency compressor, when the working mode is arefrigerating mode.
 8. The method according to claim 1, wherein a secondpressure detecting signal is detected via a second pressure sensordisposed at an outlet of the variable-frequency compressor, when theworking mode is a heating mode.
 9. The method according to claim 8,wherein performing a variable-frequency control on thevariable-frequency compressor according to the target refrigerantsaturation temperature comprises: generating a current refrigerantsaturation temperature by selecting one of the first pressure detectingsignal and the second pressure detecting signal according to the workingmode; and performing the variable-frequency control on thevariable-frequency compressor according to the target refrigerantsaturation temperature and the current refrigerant saturationtemperature.
 10. The method according to 2, further comprising:controlling the outdoor apparatus to delay a second predetermined periodto start or stop after receiving the on-off instruction.
 11. An outdoorapparatus of an air conditioning system, comprising: avariable-frequency compressor; a controller configured to control thevariable-frequency compressor and comprising: a start module configuredto obtain a working mode of the air conditioning system and to start thevariable-frequency compressor according to the working mode of the aircondition; a temperature control module configured to obtain a targetrefrigerant saturation temperature, to obtain a working time of thevariable-frequency compressor and a stop-start number of time of thevariable-frequency compressor in a first predetermined period during anvariable-frequency control for the variable-frequency compressor, and toadjust the target refrigerant saturation temperature according to theworking time of the variable-frequency compressor and the stop-startnumber of time of the variable-frequency compressor in the firstpredetermined period; and a variable-frequency control module configuredto perform the variable-frequency control on the variable-frequencycompressor according to the target refrigerant saturation temperature.12. The outdoor apparatus of an air conditioning system according toclaim 11, wherein the temperature control module is further configuredto set an adjusted target refrigerant saturation temperature as therefrigerant saturation temperature of the outdoor apparatus in a nextstart, when the outdoor apparatus is stopped.
 13. The outdoor apparatusof an air conditioning system according to claim 11, wherein thetemperature control module is further configured to adjust the targetrefrigerant saturation temperature according to a predetermined steplength, when the working time of the variable-frequency compressor islarger than or equal to a first time threshold and the stop-start numberof time of the variable-frequency compressor in the first predeterminedperiod is larger than or equal to a first predetermined number of timethreshold.
 14. The outdoor apparatus of an air conditioning systemaccording to claim 13, wherein when the working mode is a heating mode,the temperature control module reduces the target refrigerant saturationtemperature by the predetermined step length and returns the workingtime of the variable-frequency compressor to zero; when the working modeis a refrigerating mode, the temperature control module increases thetarget refrigerant saturation temperature by the predetermined steplength and returns the working time of the variable-frequency compressorto zero.
 15. The outdoor apparatus of an air conditioning systemaccording to claim 11, further comprising: a temperature sensorconfigured to detect a current ambient temperature of the outdoorapparatus, wherein the temperature control module determines the targetrefrigerant saturation temperature according to the current ambienttemperature of the outdoor apparatus, when the outdoor apparatus isstarted for the first time in a predetermined working cycle.
 16. Theoutdoor apparatus of an air conditioning system according to claim 11,further comprising: a first pressure sensor disposed at an inlet of thevariable-frequency compressor and configured to detect a first pressuredetecting signal, when the working mode is a refrigerating mode.
 17. Theoutdoor apparatus of an air conditioning system according to claim 16,further comprising: a second pressure sensor disposed at an outlet ofthe variable-frequency compressor and configured to detect a secondpressure detecting signal, when the working mode is a heating mode. 18.The outdoor apparatus of an air conditioning system according to claim17, wherein the temperature control module is further configured togenerate a current refrigerant saturation temperature by selecting oneof the first pressure detecting signal and the second detecting signalaccording to the working mode and to obtain a target refrigerantsaturation temperature, and the variable-frequency control module isconfigured to perform the variable-frequency control on thevariable-frequency compressor according to the target refrigerantsaturation temperature and the current refrigerant saturationtemperature.
 19. An air conditioning system comprising an outdoorapparatus, the outdoor apparatus comprising: a variable-frequencycompressor; a controller configured to control the variable-frequencycompressor and comprising: a start module configured to obtain a workingmode of the air conditioning system and to start the variable-frequencycompressor according to the working mode of the air condition; atemperature control module configured to obtain a target refrigerantsaturation temperature, to obtain a working time of thevariable-frequency compressor and a stop-start number of time of thevariable-frequency compressor in a first predetermined period during anvariable-frequency control for the variable-frequency compressor, and toadjust the target refrigerant saturation temperature according to theworking time of the variable-frequency compressor and the stop-startnumber of time of the variable-frequency compressor in the firstpredetermined period; and a variable-frequency control module configuredto perform the variable-frequency control on the variable-frequencycompressor according to the target refrigerant saturation temperature.20. The air conditioning system according to claim 19, wherein thetemperature control module is further configured to adjust the targetrefrigerant saturation temperature according to a predetermined steplength, when the working time of the variable-frequency compressor islarger than or equal to a first time threshold and the stop-start numberof time of the variable-frequency compressor in the first predeterminedperiod is larger than or equal to a first predetermined number of timethreshold.